This application and its disclosure generally relate to the field of determining orientation of a human head in three-dimensional geometric modeling.
Head orientation measurements in 3D geometric modeling are currently based on a combination of measurements determined by different gyroscopes, accelerometers and electronic compasses. For example, one such system is based on measurements provided by a three-axis accelerometer and a resonator gyroscope mounted on a headgear.
Other methods and measuring systems, currently in use, utilize dual inclinometers, bubble goniometers, radiographs, compass technology, visual estimation, ultrasound, geometric methods, digital optoelectronic instruments, computerized kinematic analysis using passive markers and infrared TV cameras, MRI or sensors attached to the subject's head for head orientation determination. However, none of the existing methods yield a sufficient accuracy in defining the neutral position of a human head in three-dimensions.
This lack of a precise definition of the neutral position of the 3D orientation of the human head is a serious disadvantage in current 3D geometric modeling, especially when one needs to determine some specific measurements and orientation of the human head during motion. In certain applications, for example in dental arts, the existing methods result in significant errors and distortions in the subject's measurements and, consequently, in the resulting 3D model.